EP0178656A1

EP0178656A1 - Method and apparatus for separating from excavated materials the fine and coarse constituents thereof

Info

Publication number: EP0178656A1
Application number: EP85113149A
Authority: EP
Inventors: Leif Carlsson
Original assignee: PRODEC INTER AB
Current assignee: PRODEC INTER AB
Priority date: 1984-10-18
Filing date: 1985-10-16
Publication date: 1986-04-23
Also published as: SE8405199D0; FI854037A0; FI83796B; JPS6198832A; US4805703A; AU579899B2; AU4877885A; SE8405199L; DE3562787D1; CA1277633C; FI83796C; SE454096B; JPH0796797B2; EP0178656B1; FI854037L; ATE34418T1

Abstract

This invention relates to a method of separating from excavated materials (2) fine constituents (3), preferably topsoil, and coarse constituents (4), preferably stones, roots or root crops, in which the materials to be excavated (2) are excavated by an excavating and separating bucket (11) of grid structure, which is subjected to separating movements to cause the fines (3) to escape from the excavating and separating bucket (11) through apertures provided for that purpose. To produce shock-free separating movements said method is characterized in that the excavating and separating bucket (11) is rotated continuously through one or preferably a plurality of revolutions in the same direction of rotation (R).

A simple apparatus for carrying the method of the invention into effect is characterized in that the excavating i and separating bucket (11) is comprised in a unit (5) provided with connecting means (7) to permit connection of the unit (5) to an excavating and elevating assembly (8) on a vehicle (9). Furthermore, the unit (5) comprises a rotation assembly (10) to rotate the excavating and separating bucket (11) continuously through one or preferably more revolutions in the same direction of rotation (R) to produce shock-free separating movements, and the excavating and separating bucket (11) has one or more, preferably four, pockets which are adapted to elevate the excavated materials (2) contained in the excavating and separating bucket (11) at every revolution and let them down again into the lowermost portions of the excavating and separating bucket (11).

Description

This invention relates to a method of separating from excavated materials fine constituents, preferably topsoil, and coarse constituents, preferably stones, roots or root crops, in which the materials to be excavated are excavated by an excavating and separating bucket of grid structure, which is subjected to separating movements to cause the fine constituents to escape from the excavating and separating bucket through apertures provided for that purpose. Moreover, the invention concerns an apparatus for carrying the method of the invention into effect.
US patent specification No. 683 775 describes a dipper for receiving and screening fine and coarse constituents of collected rock. The dipper has openings in its sides and is mounted on an excavator so as to be elevated, and screening takes place in that the fine constituents drop out of the openings.
US patent specification No. 3 072 257 and UK patent application No. 1 291 555 describe screening buckets subjected to reciprocating rocking or tilting movements for an increased screening effect, and US patent specification No. 3 461 968 describes a screening scoop which instead is vibrated for an increased screening effect.
The problem of subjecting screening or separating buckets to reciprocating shaking or vibrating movements is that these movements are transmitted to the frame and/or the vehicle on which the bucket is mounted. This implies that violent shaking movements and/or vibrations are transmitted to the equipment and/or the personnel with the ensuing very great risk of material fatigue and/or bodily injury. The said risk increases the more intense the shaking movements for further improvement of the separating effect. Intense shaking movements and/or vibrations will also generate inconvenient noise.
As for pivotment of buckets, international patent application WO 82/01022 teaches such pivotment for setting the bucket into various positions relative to an initial position. The pivotment setting the bucket into various angular positions is intended entirely for permitting the bucket to be set for excavation or both horizontal and inclined areas and does not therefore provide any solution of the problem how to eliminate troublesome shaking movements, vibrations and noise in separating work.
The primary object of the present invention is to provide a method for effective separation of the materials excavated by excavating and separating means without generation of troublesome shaking movements, vibrations and noise. This is realized by the invention substantially in that the excavating and separating bucket of grid structure is rotated continuously through one or preferably a plurality of revolutions in the same direction of rotation to produce shock-free separating movements.
By continuously rotating the excavating and separating bucket which is designed for effective excavation of the materials,together with the materials collected in said bucket through one or more revolutions in the same direction of rotation there are only generated gentle movements instead of violent shaking movements or vibrations which have an injurious effect on equipment or personnel after a short time of operation. Inconvenient noise is not either produced but separation takes place substantially without shocks and without essential noise.
An apparatus suitable for carrying the method of the invention into effect presents the characteristic features appearing from appendant claim 10.
The invention will now be elucidated more in detail with reference to the accompanying drawings, in which

fig. 1 is a perspective view illustrating an excavating and separating bucket for use in the method of the invention;
fig. 2 is a side view of the excavating and separating bucket;
fig. 3 is a front view of the excavating and separating bucket;
fig. 4 is a section taken on line IV-IV i fig. 3;
fig. 5 illustrates the rear part of an excavating and separating bucket of alternative design; and
fig. 6 - 11 illustrate various phases of the method of invention.

The separating apparatus 1 shown in the drawings is primarily intended for excavating and separating collected masses of earth 2 to separate fine constituents 3, such as topsoil and coarse constituents 4, such as roots, twigs 4a, stones and the like. The separating apparatus 1 comprises a separate unit 5 which has a frame 6 with connecting means 7 for connection of the unit 5 with an excavating and/or elevating assembly 8 of a vehicle 9, such as a tractor shovel wheeled loader or excavating machine. The connecting means 7 are so designed that the excavating and/or elevating assembly 8 of the vehicle 9 can be brought into engagement with said connecting means when the unit 5 stands on the ground. When the connecting means 7 and the excavating and/or elevating assembly 8 are connected they can be interlocked by means of latches (not shown). The frame 6 comprises a rotation assembly 10, which is adapted to rotate an excavating and separating bucket 11 of grid structure continuously through one or a plurality of revolutions in one and the same direction of rotation R to produce shock-free separation movements.
In the embodiment according to fig. 4 the rotation assembly 10 is an hydraulic assembly 10a of the type customarily used to drive the drive wheels of forestry machinery. The hydraulic assembly 10a can be connected via conduits 12 and 12a to a hydraulic system 13 inherent in the vehicle so as to be driven with the aid of said system. In the embodiment of fig. 4 the rear end wall 14 of the excavating and separating bucket 11 is retracted into the excavating and separating bucket 11 and the retracted portion constitutes a shield 15 to which the hydraulic assembly 10a is bolted and which screens off said hydraulic assembly 10a from the interior 16 of the excavating and separating bucket 11. Said retraction of the hydraulic assembly 10a within the excavating and separating bucket 11 implies that the total length of the unit 5 will be smaller than the combined lengths of the excavating and separating bucket 11 and the hydraulic assembly 10a.
In the embodiment of fig. 5 the rotation assembly 10 is an hydraulic assembly 10b which is connected to the hydraulic system 13 of the vehicle 9 in the same way as the hydraulic assembly 10a according to fig. 4. In this case the hydraulic assembly 10b carries on its output drive shaft a gear 17 which is in driving engagement with a gear rim 18 bolted to the rear end wall 14 of the excavating and separating bucket 11. Said end wall may in this instance be planar since the gear rim 18 can bear directly against the outer face of the end wall 14 and since the gear rim 18 per se need not be of a large width, and moreover the hydraulic assembly 10b can be spaced a rather great distance from the connecting means 7.
The rotation assembly 10 is adapted to rotate the excavating and separating bucket 11 about the axis of rotation 19, and to ensure the requisite uniform rotation it is advantageous to dispose the excavating and separating bucket 11 at least tolerably centered in relation to said axis of rotation 19. The excavating and separating bucket 11 has four forwardly extending sides 20, 21, 22 and 23 with apertures 24 therein for fine constituents 3, i.e. in the present case for topsoil. The sides 20-23 in this case consist of circumferentially extending rods 25 which are interconnected be means of forwardly directed stays 26 so that the rods 25 and the stays 26 together form a grid structure 27. For rigidifying purposes, two or more stays 28, 29 may be arranged within the excavating and separating bucket 11 between the shield 15 and the sides 20 - 23 of the excavating and separating bucket 11 in front of the shield 15.
In the interior 16 of the excavating and separating bucket 11 the sides 20-23 thereof together form a corner 30a, the sides 21 and 23 together form a corner 30b, the sides 23 and 22 together form a corner 30c and the sides 22 and 20 together form a corner 30d. Said corners 30a-30d are adapted, during the rotation of the excavating and separating bucket 11, to form four pockets for the masses of earth 2 in the interior 16 of the excavating and separating bucket 11, and each such pocket 30a-30d carries along a large part of the initial mass of earth 2 therein in an upward direction until the respective pocket 30a-30d approaches or reaches its uppermost position, while another part of the initial mass of earth 2 in said pocket is not carried along but slides down along one of the sides 20 - 23. When the respective pocket 30a-30d approaches or reaches the uppermost position the upwardly moved portion of the mass of earth 2 cannot any longer retain its hold in the pocket but falls freely downwards in the excavating and separating bucket 11 landing up on the portion of the masses of earth 2 at the bottom of the excavating and separating bucket 11.
By causing portions of the masses of earth 2 to fall down in the excavating and separating bucket 11 in the manner indicated it is realized that the clods of earth falling down and/or lying at the bottom of the excavating and separating bucket 11 are comminuted. The stones falling down together with the upwardly moved portion of the masses of earth 2 highly contribute to said comminution as they hit earth clods during or at the end of their fall.
Considering that the excavating and separating bucket 11 in the embodiment illustrated has four sides 20-23 which form four corners and thus four pockets 30a-30d, portions of the mass of earth will be raised and fall down four times for every revolution.
The'excavating and separating bucket 11 illustrated may be provided with further pockets (not shown) arranged in or on one or more of the sides 20-23, and pockets may be formed by outwardly curving side portions (not shown), inwardly curving side portions or vane-like drivers (not shown) mounted on the sides and protruding inwardly therefrom.
With a trilateral excavating and separating bucket 11 instead of a quadrilateral one, the sides instead form three corners which can be utilized as pockets to carry along masses of earth in an upward direction. Also a trilateral embodiment of the excavating and separating bucket 11 may have more than three pockets for carrying along masses of earth. In the same way an excavating and separating bucket design having five sides may present five or still more pockets for carrying along masses of earth, a hexahedral excavating and separating bucket design may present six or more pockets for carrying along masses of earth, etc.
The excavating and separating bucket 11 has a front opening 30 for receiving the mass of earth 2 and for discharging such coarse constituents 4 as will remain in the excavating and separating bucket 11 after fines 3 have been. screened through the apertures 24 in the sides 20-23. To facilitate reception of masses of earth 2 in the excavating and separating bucket 11 the side 20 at the front opening 30 has a forwardly directed excavating or cutting blade 31.
To prevent or at least effectively counteract that portions of the masses of earth 2 fall out of the opening 30 of the excavating and separating bucket 11 when said bucket 11 is rotated to cause the fines 3 to fall out of the apertures 24 in the sides 20-23 of the excavating and separating bucket 11 the sides 21, 22 and 23 at the front have retracted portions 21a, 22a and 23a. The side 20 having the excavating blade 31 is not retracted (or but slightly retracted). In order that also this side 20 shall effectively counteract that portions of the masses of earth 2 fall out, the excavating blade 31 has a number of upstanding flange means 31a which extend rearwardly a distance into the excavating and separating bucket 11. Said flange means 31a extend in parallel with the excavating direction in order not to obstruct the masses of earth 2 during the excavating operation. The flange means 31a are of such a height and have such a steeply inclined inside 31b as not to prevent roots, twigs, large stones and other large constituents 4 in the mass of earth 2 from escaping by catching them at the rotation of the separating means.
The rear end wall 14 may be formed as a shield so that masses of earth cannot fall down onto the rotation assembly 10 and/or other parts located at the rear of the excavating and separating bucket 11. Alternatively, the end wall 14 may present apertures for fines 3, especially if it does not matter whether earth falls down on parts of the unit 5 and/or the excavating and/or elevating assembly 8 located at the rear of the excavating and separating bucket 11.
For the separation of masses of earth the vehicle is driven up to the unsorted masses of earth 2 and if the excavating blade 31 is not at the very bottom in a horizontal excavating position S the excavating and separating bucket 11 is rotated until the excavating blade 31 occupies said excavating position S (cf. fig. 6). If it is desired to set the excavating blade 31 into a position oblique to the horizontal position, the bucket 11 is rotated until the excavating blade 31 reaches such a position, whereupon the bucket 11 is locked against rotation. Then the excavating and separating bucket 11 is moved into the masses of earth 2 (arrow A), the excavating blade 31 facilitating the penetration. When the lower parts of the excavating-and separating bucket 11 have been filled with a suitable amount of mass of earth 2 the excavating and separating bucket 11 is raised to a position of rotation (cf. fig. 7) and if coarse constituents 4 in the form of roots or twigs 4a hang out of the front opening 30 the excavating and separating bucket 11 may be rotated (arrow B) through one or two revolutions so that the roots or twigs 4a drop back onto the spot of collection 33. This will prevent roots and twigs 4a falling down at a wrong spot.
The vehicle 9 is now driven to a location 34 where the fines 3, i.e. in this instance topsoil, are to be deposited. In the present case this location is a large lot which is to be covered with a rather thin layer of topsoil to permit the sowing of grass. When the excavating and separating bucket 11 has been placed in the correct position at the location 34 (fig. 9), the bucket is rotated in its position of rotation continuously through the number of revolutions in the same direction of rotation (arrow P) that is required for all fines 3, i.e. all topsoil, to escape from the excavating and separating bucket 11.
The separating movement being a continuous movement of rotation, which takes place in the same direction of rotation, there is obtained an effective and entirely shock-free separation, whereby neither equipment or personnel is subjected to intense shocks, shaking movements, vibrations and noise. By continuous movement of rotation in the same direction R through a plurality of revolutions there is more precisely understood that the excavating and separating bucket 11 is rotated without interruptions and/or without reciprocatory movements through one or more revolutions because such changes in the movement of rotation would necessitate sudden stops of the excavating and separating bucket with its contents.
At the rotation of the excavating and separating bucket 11 the masses of earth 2 contained in the pockets 30a-30d of the bucket 11 are caused to follow said pockets in an upward direction in order again to drop down into the lower parts of the excavating and separating bucket 11. This is repeated four times per revolution, whereby an effective comminution of comminutable constituents of the masses of earth 2 is obtained. During the rotation the fines 3 fall out of the bucket little by little while the coarse constituents 4 remain and go on partaking in the comminution process. As a result, the separation will be so efficient that not very many revolutions (for instance, but fifty revolutions) will be required until an excavating and separating bucket 11 which is rather well filled with earth 2 is emptied of its fines 3. It has proved that the height of fall in the excavating and separating bucket 11 can be maintained within the limits of an efficient separation and simultaneously such that the drop of the masses of earth will not give rise to undesirable vibrations.
The speed of rotation is kept within the range of 25-35 r.p.m., that is, it is about 30 r.p.m., as this r.p.m. has proved very advantageous for the separation of topsoil from masses of earch 2 collected by means of an excavating and separating bucket 11 which is of a design and of a suitably large size to permit efficient excavation when the masses of earth 2 are to be collected by means of said bucket. The speed of rotation may, however, be varied in dependence on the type of materials and/or amount of materials, but in most cases a speed of rotation of 25-40 r.p.m. is sufficient for efficient separation. Even if the speed of rotation in increased to almost 40 r.p.m. or more, the excavating and separating bucket 11 retains its "gentle run", i.e. no inconvenient shaking movements of noise arise even at such high r.p.m.
During the rotation at location 34 the vehicle 9 may be propelled slowly (arrow C) to distribute the fines 3 dropping down, until every larger surfaces of the location 34 are covered with topsoil 3. The only directly manual work that need then be done before e.g. grass is sown, is that the surface of the topsoil layer is levelled with the aid of a suitable tool. All heavy operations in connection with separation and transport have, however, been eliminated.
Whenever the excavating and separating bucket 11 contains a large amount of earth 2 it is preferably rotated in a slightly rearwardly inclining position, that is, it is rotated about the inclined axis of rotation 19a, fig. 9, in which position those parts 32 of the excavating and separating bucket 11 which are lowermost and extend rearwardly from the opening 30, are inclined rearwardly and downwardly. When so large a portion of the fines 3 has dropped out of the excavating and separating bucket 11 that material is left only in the rear parts of the bucket 11, said bucket 11 may be tilted slightly forwardly until it occupies a position in which the lowermost part 32 extends substantially horizontally (position 32a).
The excavating and separating bucket 11 is rotated in this case about a substantially horizontal axis of rotation 19b, fig. 9. It is hereby ensured that the masses of earth 2 are distributed better over the entire length of the excavating and separating bucket 11, i.e. the bucket 11 is exploited to a higher extent and the separation becomes more efficient.
If a smaller amout of earth 2 is excavated at a time by the bucket 11 the latter can be adjusted into a horizontal position of rotation from the very beginning. Such portions of the masses of earth 2 as reach the front parts of the excavating and separating bucket 11 during the rotation are prevented with the aid of the retracted side portions 21a, 22a, 23a and the flange means 31a from dropping out of the opening 30. When the excavating and separating bucket 11 has been emptied of fines 3 to the requisite extent the vehicle 9 is driven away (arrow P, fig. 10) for emptying of the coarse constituents at a location 35 intended for that purpose. At this location 35 the excavating and separating bucket 11 is tipped forwardly and downwardly with the aid of the excavating and/or elevating assembly 8. To accelerate emptying of the excavating and separating bucket 11, the latter may be rotated (arrow E, fig. ll) when it occupies the tipping position. The vehicle 9 is then driven back to location 33 for collection of fresh masses of earth 2 in the excavating and separating bucket 11, whereupon the abovementioned separation procedure is repeated.
The entire collection, separation and tipping process can be carried out in one sequence without interruption, and it has proved that after a short training period considerable amounts of earth can be separated without subjecting equipment and personnel to troublesome shaking movements of vibrations.
By way of alternative of the device described it may be mentioned that the rotation assembly may be an assembly of another type, such as an electrically operated motor or diesel-driven engine. The excavating and separating bucket may have any other number of sides than four, and instead of being a grid structure the bucket may be provided with perforated sides. The sides of the excavating and separating bucket 11 may be retracted in their entire length instead of but parts thereof being retracted. The excavating blade may possibly be formed by the very edge of the opening 30, or excavating blades may be formed by, or arranged on, more than one edge. The flange means 31a may have a shape other than the one illustrated, their number may vary and they may be provided on more than one side, e.g. on all four sides.
In exceptional cases it may be sufficient to rotate the excavating and separating bucket 11 continuously through one or possibly somewhat less than one revolution for the requisite separation of fines, but generally a plurality of revolutions are required for the separation of most materials.
The excavating and separating bucket 11 may to advantage also be placed above the platform of a truck and rotated in this position. This will permit simultaneous separation and loading of fines.
The separating method and separating apparatus described are particularly suitable for separation of topsoil from stones, roots and twigs in masses of earth, but may alternatively be used for separation of fine and coarse constituents in other kinds of excavated materials, e.g. stone--containing gravel material. The method and the apparatus may also be used with excavated material in the form of root crops, such as sugar beets with adhering soil, where it is intended to detach the soil from the root crops and to separate the root crops and the detached soil.

Claims

1. A method of separating from excavated materials fine constituents (3), preferably topsoil, and coarse constituents (4), preferably stones, roots or root crops, in which the materials (2) to be excavated are excavated by an excavating and separating bucket (11) of grid structure, which is subjected to separating movements to cause the fine constituents (3) to escape from the excavating and separating bucket (11) through apertures (24) provided for that purpose, characterized in that the excavating and separating bucket (11) of grid structure is rotated continuously through one or preferably a plurality of revolutions in the same direction of rotation (R) to produce shock-free separating movements.

2. A method as claimed in claim 1, characteri- zed in that the excavating and separating bucket (11) is rotated when it occupies a position in which the lowermost portions (32) of the excavating and separating bucket (11) that extend between a rear end wall (14) and a front opening (30) for discharging coarse constituents (4) and that contain excavated materials (2), run substantially horizontally (position 32a).

3. A method as claimed in claim 1 or 2, characteri-zed in that the excavating and separating bucket (11) is first rotated when it occupies a position in which lowermost portions (32) of the excavating and separating bucket (11) that extend between a rear end wall (14) and a front opening (30) for discharging coarse constituents (4) and that contain excavated materials (2), are rearwardly inclined, whereafter the excavating and separating bucket (11) is rotated when it occupies a position in which the lowermost portions (32) of the excavating and separating bucket (11) that extend between a rear end wall (14) and a front opening (30) for discharging coarse constituents (4) and that contain excavated materials (2), run substantially horizontally (position 32a).

4. A method as claimed in any one of the preceding claims, characterized in that the excavated materials (2) in the excavating and separating bucket (11) at the rotation thereof are elevated within the excavating and separating bucket (11) and let down to the lowermost portions of said bucket a number of times, preferably four times, per revolution.

5. A method as claimed in any one of·the preceding claims, characterized in that the excavating and separating bucket (11) is rotated at a speed of rotation of 20-40 r.p.m., preferably 25-35 r.p.m., to cause the fines (3) to fall out of the apertures (24) provided for that purpose.

6. A method as claimed in any one of the preceding claims, characterized in that the excavating and separating bucket (11) under rotation is moved to a location (34) for the fines (3) to distribute said fines (3) at said location (34) as separation proceeds.

7. A method as claimed in any one of the preceding claims, characterized in that the excavating and separating bucket (11) is rotated to, and locked in, a position in which an excavating blade (31) disposed at a front opening (30) for receiving excavated materials (2) and discharging coarse constituents (4), occupies a horizontal excavating position or an excavating position inclined to the horizontal, whereupon the parts of the excavating and separating bucket (11) having excavating blades (31) are moved into the materials (2) to be excavated for collection of said materials (2) in the excavating and separating bucket (11), which is then moved to, and rotated at, a location (34) at which the fines (3) of the collected materials (2) is to be deposited.

8. A method as claimed in claim 7, characteri- zed in that the excavating and separating bucket (11) is rotated above the location (33) for collection of excavated materials (2) to cause such coarse constituents (4a) as at the collection hang out of the front opening (30) of the excavating and separating bucket (11), to drop down again onto the collection location (33).

9. A method as claimed in any one of the preceding claims, characterized in that the excavating and separating bucket (11), after the sorting of the fines (3), is tipped and rotated in the tipping position at a location (35) for collection of coarse constituents (4) to facilitate dropping of the coarse constituents (4) out of the excavating and separating bucket (11) through an opening (30) provided for that purpose.

10. An apparatus for carrying into effect the method of separating from excavated materials (2) fine constituents (3), preferably topsoil, and coarse constituents (4), preferably stones, roots or root crops, in which the materials (2) to be excavated are excavated by an excavating and separating bucket (11) of grid structure which is subjected to separating movements to cause the fine constituents (3) to escape from the excavating and separating bucket (11) through apertures (24) provided for that purpose, characterized in that the excavating and separating bucket (11) is comprised in a unit (5) provided with means (7) to permit connecting the unit (5) to an excavating and/or elevating assembly (8) on a vehicle (9), and that the unit (5) comprises a rotation assembly (10) for rotation of the excavating and separating bucket (11) continuously through one of preferably more revolutions in the same direction of rotation (R) to produce shock-free separating movements, the excavating and separating bucket (11) having one or more, preferably four pockets (30a-30d) which are adapted to elevate the masses of earth (2) contained in said excavating and separating bucket (11) at every revolution and let said masses drop down again to the lowermost portions of the excavating and separating bucket (11).

11. An apparatus as claimed in claim 10, characteri-zed in that the excavating and separating bucket (11) presents a plurality of, preferably four, sides (20-23), which at the rotation of the excavating and separating bucket (11) rotate about an axis of rotation (19) and which together form the pocket or pockets (30a-30d) and are provided with apertures (24) to let through the fines (3) of the mass of earth (2), the excavating and separating bucket (11) having a rear end wall (14) which is connected to the rotation assembly (10), while the opposite face of the rear end wall (L4) is open to form a front opening (30) for letting coarse constituents (4) out of the excavating and separating bucket (11).

12. An apparatus as claimed in claim 11, characteri-zed in that at least one (20) of the edges of the front opening (30) is provided with or formed as an excavating blade (31).

13. An apparatus as claimed in claim 10 or 11, charac-terized in that at least one of the sides (20-23) having apertures (24) for fines (3) are retracted in their entire length or parts (21a, 22a, 23a) of their length as seen in a forward direction toward the front opening (30) to constitute an inner space (16) in the excavating and separating bucket (11), which space tapers forwardly toward the front opening (30).

14. An apparatus as claimed in any one of claims 10-13, characterized in that the excavating and separating bucket (11) is provided with flange means (31a) extending inwardly into a front opening (30) for receiving excavated materials (2) and discharging coarse constituents (4), said flange means being disposed at least at one edge of the opening (30) which forms or is provided with an excavating blade (31), or at more of the edges forming the opening (30).

15. An apparatus as claimed in anyone of claims 10-14, characterized in that the rotation assembly (10) is an hydraulic assembly (10a) of the type used to drive the drive wheels of forestry machinery, the rotation assembly (10) being connedtable to a hydraulic system (13) of the vehicle (9) for the operation thereof and the hydraulic assembly (10a) being preferably disposed within the excavating and separating bucket (11) separated from the interior (16) of said bucket (11) by means of a shield (15) to which the hydraulic assembly (10a) is bolted.

16. An apparatus as claimed in claims 10-14, charac- terized in that the rotation assembly (10) is an hydraulic assembly (10b) which is connectable to a hydraulic system (13) of the vehicle (9) for the operation thereof and which via a gear (17) drives a gear rim (18) fixedly connected to the excavating and separating bucket (11), said gear rim (18) being preferably disposed on the outer face of a rear end wall (14) of the excavating and separating bucket (11).

17. An apparatus as claimed in claims 10 - 16, charac-terized in that the sides (20-23) of the excavating and separating bucket (11) having apertures (24) for fines (3) entirely or partly consist of a grid structure (27) and that the excavating and separating bucket (11) has an imperforate rear end wall (14) by which it cooperates with the rotation assembly (10).